PROBLEM TO BE SOLVED: To provide a bone filling material kit from which a pasty bone filling material, that exhibits both of satisfactory flowability when filled and high strength after hardened, can be produced.SOLUTION: The bone filling material kit comprises: fine particles of a calcium phosphate-based compound and an aqueous medium. The fine particles of the calcium phosphate-based compound have 15.0 to 45.0 vol.% of the content of fine particles having the particle size equal to or larger than 10 &mum and smaller than 100 &mum.